export function RecordingData(audioData) {
  let output = to16kHz(audioData)
  output = to16BitPCM(output)
  output = Array.from(new Uint8Array(output.buffer))
  // self.postMessage(output)
  return output
}

function to16kHz(audioData) {
  const data = new Float32Array(audioData)
  const fitCount = Math.round(data.length * (16000 / 44100))
  const newData = new Float32Array(fitCount)
  const springFactor = (data.length - 1) / (fitCount - 1)
  newData[0] = data[0]
  for (let i = 1; i < fitCount - 1; i++) {
    const tmp = i * springFactor
    const before = Math.floor(tmp).toFixed()
    const after = Math.ceil(tmp).toFixed()
    const atPoint = tmp - before
    newData[i] = data[before] + (data[after] - data[before]) * atPoint
  }
  newData[fitCount - 1] = data[data.length - 1]
  return newData
}

function to16BitPCM(input) {
  const dataLength = input.length * (16 / 8)
  const dataBuffer = new ArrayBuffer(dataLength)
  const dataView = new DataView(dataBuffer)
  let offset = 0
  for (let i = 0; i < input.length; i++, offset += 2) {
    const s = Math.max(-1, Math.min(1, input[i]))
    dataView.setInt16(offset, s < 0 ? s * 0x8000 : s * 0x7fff, true)
  }
  return dataView
}
